TKL rations were, in an alternate timeline, standard ration packs dispensed aboard the battleship Enterprise-D. TKLs were one of the few foodstuffs available aboard the ship due to the ongoing conflict between the Federation and the Klingon Empire. Replicators were on minimal power to maximize energy available to defensive systems. Tasha Yar ordered a TKL from Guinan and explained their purpose to a confused Richard Castillo. (TNG: "Yesterday's Enterprise")